WO1996032972A1 - Method and device for the vascular pressure-controlled selective perfusion of fluids through blood vessels - Google Patents

Abstract

The invention concerns a method and device for the selective perfusion of fluids through blood vessels, controlled by the pressure in the blood vessel. The invention particularly concerns the aspiration of a fluid out of and retroinfusion of the fluid into veins, in particular coronary veins, controlled by the pressure in the vein, and the perfusion of fluids through arteries, in particular coronary arteries, controlled by the pressure in the artery. The retroinfusate is pumped into the blood vessel (200) through tubing (60) which is open at the proximal end and can be inserted into a vein or artery (200) of the patient. For retroinfusion from veins, the tubing (60) is connected to a suction device (90) for blood or retroinfusate from the patient's vein (200). A control unit (10) derives commands from ECG signals to synchronize the pumping and aspiration intervals with the patient's heart cycle. During the pumping phases, the intravenous or intra-arterial pressure is measured, and the control unit (10) maintains the pressure inside the blood vessel as constant as possible at a given level during the intervals between pumping by means of a flow regulator (30).

Description

 Method and device for the vascular pressure-controlled selective perfusion of body vessels with fluids

The present invention relates to a method and a device for vascular pressure-controlled selective perfusion of body vessels with fluids. In particular, the present invention relates on the one hand to the venous pressure-controlled suction and retroinfusion of a fluid from or in body veins, in particular coronary veins, and on the other hand to the artery pressure-controlled perfusion of body arteries, in particular coronary arteries.

The nutritive perfusion of coronary arteries or the retroinfusion of blood in coronary veins plays an increasingly important role, particularly in the area of myocardial protection during short-term coronary artery occlusion as part of a cardiological intervention. A typical intervention of this type is, for example, balloon dilation of an atherosclerotically narrowed coronary artery. In this method, also known as percutaneous transluminal coronary angioplasty (PTCA), a balloon catheter is guided under X-ray control into the area of the stenosis of the coronary artery and the arteriosclerotic plaque is compressed by inflating the balloon located at the end of the catheter. During the dilation of the balloon, there is no supply of oxygenated blood to the tissue downstream in the artery. This is usually not a problem as long as the dilatation is short-lived. However, functional dilatations in the ischaemia area of the

Determine myocardium, for example electrocardiographically as S-T changes, echocardiographically as reduced regional wall movement or subjectively as angina pectoris complaints of the patient. In addition, the risk of complications from angioplasty is certain

Patient groups increased, for example in the elderly, in the presence of unstable angina pectoris, in the case of decreased left ventricular ejection fraction or dilatation of a vessel that supplies more than 40% of the left ventricle.

Corresponding problems of the ischemia protection of the myocardium also arise in other interventions

Coronary vascularization such as for atherectomy, coronary arthroplasty and laser applications.

It is known to carry out a short-term ischemia protection by machine perfusion of an artery supplying the affected myocardial region, for example the artery itself to be dilated, either with arterial blood which has been taken from the patient elsewhere or with other nutritive fluids. However, there is a risk that the myocardial tissue will be over-perfused, which is particularly the case if the outflow of the perfused fluid from the affected tissue is obstructed or completely blocked. In such cases, hemorrhagic tissue infarction in the affected myocardial region can occur.

As another short term option

Ischemia protection has been performing a retroinfusion of arterial blood into a vein of the relevant ischemic area of the myocardium for some time in cases where complications are expected. The arterial blood is pumped through the appropriate vein into the nutritive capillaries of the ischemia area and thus supplies the myocardium in this region with oxygen and substrates.

Devices for retroinfusing coronary veins have been known for several years. For example, a retroinfusion device is described in European Patent EP-B-0 297 723, with which arterial blood, for example from the arteria femoralis, is taken from the patient and one via a pump system and an inflatable balloon catheter

Coronary vein of the ischemic area is supplied. The pumping of arterial blood into the coronary vein is done with the R wave an electrocardiogram of the patient synchronized so that the pumping interval is adapted to the patient's cardiac cycle. The pump interval is fixed and begins at 45% of the RR interval and ends at 95% of the RR interval. The infused blood flow is essentially constant during the pump interval. While pumping, the balloon of the balloon catheter is inflated and blocks the vein, ensuring that arterial blood is effectively transported into the ischemic area during diastole. The pumping process ends at the end of the diastole and the balloon is deflated so that the flow in the vein is no longer blocked at this point. During the subsequent systole, venous blood can flow out through the vein.

With the device described in EP 0 297 723, the basic metabolism of the ischemia area can be maintained satisfactorily during a short-term cardiological intervention. It was also observed that the size of the myocardial infarction was significantly reduced after coronary artery occlusion. However, it was also found that the local myocardial function is not adequately maintained. For example, the local myocardial function comes to a complete standstill in the absence of arterial collateralization of the ischemic area. The primary reason for this is the incomplete exchange of arterial and venous blood in the retro-infused venous system over the course of a cardiac cycle.

To improve this blood exchange with the goal of improved maintenance of myocardial function in the

To reach the ischemic area, Boekstegers et al recently proposed in Cardiovascular Research 1990, 24: 456-464 and in JACC 1994, 23: 459-469 a system for retroinfusion of coronary veins in which instead of the passive outflow of venous blood during systole active suctioning takes place through the retroinfusion catheter. For this purpose, the balloon of the catheter remains inflated and blocks the suction interval Vein also during systole. With such a device, better maintenance of myocardial function during coronary artery occlusion was demonstrated in the animal model.

However, the system still has disadvantages for clinical use on patients.

Thus, in this device, as in the device of EP 0 297 723, the pump volume per pump surge can be set, but the flow of the retro-infused blood during a pump interval cannot be influenced. It turns out, however, that the intravenous pressure is subject to strong fluctuations over the course of a pump interval. Even if you register the intravenous pressure, you can set a desired mean pressure over several pumping intervals, but the strong pressure fluctuations within one pumping interval cannot be eliminated.

However, there are some problems associated with these large changes in coronary vein pressure. Thus, it has been found that with a low retroinfusion flow, i.e. with low venous pressure, an adequate supply of oxygen to the myocardium is not guaranteed, so that the myocardial function in the ischemic area cannot be maintained. With high infusion flow, i.e. if the coronary vein pressure is too high, however, there is a risk of over-perfusion which does not improve the retrograde nutritive capillary filling, but only hinders the contraction of the myocardium and leads to an ineffective outflow of the arterial blood into the systematic circulation. With retroinfusion with too high a coronary artery pressure there is also the risk of irreversible damage to the vessel walls.

The object of the present invention is therefore to provide a method and a device for perfusing body vessels, in particular coronary vessels, in which the Perfusion is carried out at an optimal vessel pressure for the nutritive capillary filling and this target pressure is kept as constant as possible during pumping. The method according to the invention and the device according to the invention are intended to make it possible to expand the possible uses of vascular perfusion, in particular arterial perfusion and vein retroinfusion, beyond the short-term myocardial protection carried out previously.

According to the invention, a method for vascular pressure-controlled selective perfusion of body vessels with fluids is introduced, in which a hose line open at the proximal end for perfusion of a tissue region with fluids is introduced into a patient's body vessel to be perfused, the vessel being sealed off from the line in the region of its proximal end and pumps the fluid into the vessel, which is characterized in that one specifies a specific setpoint of the internal pressure of the vessel, measures the internal pressure of the vessel, and regulates the perfused fluid flow during pumping in such a way that the setpoint of the internal pressure of the vessel is adhered to as precisely as possible.

In contrast to the known perfusion methods, according to the invention the fluid flow during the pumping of fluid is no longer determined only by the pump volume per pump stroke and thus the volume flow course cannot be influenced during the pumping phase, but is regulated according to the measured vessel pressure. General methods known in measurement and control technology can be used as the regulation method, the current blood pressure in the vessel being used as the control variable and the currently infused fluid flow as the control variable. The control function can take into account the typical elastic properties of a blood vessel on the basis of predetermined parameters and, if necessary, adapt these parameters to the circumstances in the specific individual case by evaluating the dynamics of the system. In particular, the control system extrapolate the future pressure curve based on the current pressure curve and adjust the fluid flow in good time. The control system is set so that the response time is less than 25 milliseconds.

The fluid is advantageously pumped periodically into the vessel at intervals, the pumping intervals being synchronized with the heartbeat of the patient.

However, one can, especially in the case of perfusion of

Arteries that also continuously pump the fluid into the vessel.

The setpoint of the vessel pressure to be set is an individual value which depends on the respective patient, the vessel to be infused and the specific location of the perfusion in the vessel.

The setpoint of the internal arterial pressure is advantageously chosen so that nutritive perfusion is maintained.

If nutritive fluid is retroinfonded into a vein, the fluid is periodically infused into the vein via the hose line and blood is drawn out of the vein via the hose line. The pump and suction intervals are preferably synchronized with the heartbeat of the patient.

Surprisingly, it was found according to the invention that it is possible to individually determine the desired target value of the venous pressure in a separate measurement before the actual retroinfusion begins for the respective situation. According to the invention, the nominal value of the internal venous pressure is determined in such a way that, with a sealed vein, one measures the venous pressure either without retroinfusion with an existing venous blood flow, or that one with each of them if there is no blood flow

Pump interval infused increasing fluid flow and thereby measures the internal venous pressure. It is found that the The venous tip pressure does not increase in proportion to the increasing fluid flow, but rather approaches a limit value (plateau pressure). It can be assumed that the maximum retrograde nutritive capillary filling is reached at this plateau pressure, and that with higher fluid flow only an ineffective outflow into the systematic circulation takes place. According to the invention, it is therefore proposed to specify this plateau pressure as the target value for the venous pressure during the retroinfusion.

In the case of ischemia protection of the myocardium or tissue protection in general, the infused or perfused fluid is preferably an oxygen carrier. Blood is advantageously used as the oxygen carrier, with arterial blood of the patient himself being used particularly advantageously, which is taken, for example, from the arteria femoralis and via a pump, a blood filter for cleaning and an air trap for freeing the blood from air bubbles under a pressure of preferably approx. 2 bar via a flow control of the vein that is to be retro-infused. However, it is also possible to use a blood substitute, e.g. a

To use fluorocarbon or perfluorocetyl bromide solution as an oxygen carrier.

The fluid venous infused or arterially perfused to the patient can also be therapeutic or diagnostic

Active substances, e.g. Contain anticoagulants, contrast agents or ß-blockers.

If the bodily vein to be retrofused is, for example, a leg vein in which a thrombus is located, then means to dissolve this thrombus are advantageously added to the fluid. This allows, for example, high concentrations of a drug to be applied locally without adversely affecting the other bodily functions.

According to one embodiment of the method according to the invention venous blood or retroinfusate is actively drawn off between the pump phases. This blood is fed into a reservoir via a vacuum pump. In the case of a brief retroinfusion of a body vein, the amount of blood drawn out in this way is relatively small. In the case of a long-term retroinfusion, for example in the case of ischemia protection of the myocardium during a long-term coronary artery occlusion, it can be advantageous to defoam the blood drawn off in a suction interval and to free it from air bubbles and then to feed it back to the patient via a body vein. A blood loss of the patient which limits the duration of use of the method according to the invention is thus effectively avoided.

According to the invention, a device for vascular pressure-controlled selective perfusion of body vessels with a fluid, which is particularly suitable for carrying out the method described above, is provided. The device has a hose line that can be inserted into a patient's body vessel and is open at the proximal end, which can be charged with a pressurized fluid that is to be pumped into the body vessel, an expandable sealing means being provided at the proximal end that opposes the vessel the line seals, and is characterized in that also means for measuring the

Vessel internal pressure and a flow controller for the line are provided, the control unit via flow controller keeping a certain internal vessel pressure as constant as possible during pumping.

If a vein is retrofused with the device according to the invention, then the line is advantageously connected to a suction device for blood from the patient's vein and a control unit is provided which receives signals from the patient's heartbeat and defines pumping and suction intervals which correspond to the cardiac cycle of the patient Patients are synchronized. According to a preferred embodiment, the supply and suction line is a multi-path catheter. In an embodiment suitable for retroinfusion, it is an at least four-course venous catheter, a supply line for the fluid, a suction line for the drawn blood, a measuring line for determining the internal venous pressure and a control line for the expandable sealant being provided. An arterial catheter of at least three barrels is advantageously used for arterial perfusion, one of which

Supply line for the fluid, a measuring line for determining the internal artery pressure and a control line for the expandable sealant are provided.

The sealant is advantageously a pressure-controlled inflatable balloon, so that a balloon catheter can be used as the catheter. The balloon is then preferably located at the end of the catheter inserted into the blood vessel. The measuring line for determining the internal vessel pressure communicates with the inside of the vessel at one end and has a pressure sensor at its other end. However, it is also possible to arrange a pressure sensor at the proximal end of the line, which is connected to the control unit with a fine cable, which can be guided, for example, through the control line for the inflatable balloon. In this case, for example, a three-barrel catheter would be sufficient. In addition, the supply line and suction line at the proximal end of the catheter can be designed as a line, which is then connected to the supply reservoir or the suction reservoir via a switchable 3-way valve.

Depending on the task, a catheter can also be provided which contains additional lines, for example a fiber optic cable for laser applications or video recordings.

In a preferred embodiment, the flow control is designed so that the supply line in the Area of this flow control has an elastically flexible hose, the flow control comprising a clamping element operated by an electric motor, which compresses the elastic hose to a greater or lesser extent and thus controls the retro-infused flow of the fluid into the blood vessel. The electric motor is preferably a stepper motor controlled by the control unit, an eccentric mounted on the axis of the stepper motor actuating the clamping member, the clamping member preferably being designed as a crossbar oriented essentially perpendicular to the fluid supply line. The supply line rests on a rigid surface.

The distal end of the supply line is preferably connected to a pressurized reservoir for the fluid, which advantageously has a pressure sensor for monitoring the pressure in the reservoir. The supply line is supplied with the fluid to be infused from this reservoir.

In a further embodiment, this reservoir is fed with the blood drawn from an artery of the patient via a roller pump.

The suction device for the venous blood preferably has a vacuum pump and a reservoir for the sucked blood. If you want to return the sucked blood to the patient, this blood will preferably be directed into a reservoir from which it can then be supplied to a patient's vein via a roller pump, an air trap and a defoaming arrangement.

The synchronization with the patient's cardiac cycle is preferably carried out via the derivation of an electrocardiogram (EKG), the R-wave being used particularly advantageously as a trigger signal. The pump cycle advantageously begins between 15 and 50% of the RR interval and ends with the beginning of the following R wave. But it is also conceivable to vary the pumping phase within wide limits, so that it may also go beyond the following R wave of the EKG. Usually, a fixed ratio of pump phases to cardiac cycles is selected, for example 1: 1, 1: 2, 1: 3 etc. It is preferred to always suction between the individual pump phases. However, it can also be advantageous to provide phases in which there is neither pumping nor suction.

The method according to the invention and the device for controlling the coronary vein pressure during a single pumping interval have numerous advantages over the known retroinfusion devices:

In arterial perfusion, for example in the antegrade catheter perfusion of a coronary artery, the desired perfusion pressure can be maintained at both the blocked and the unblocked balloon at the tip of the catheter. The pressure can be regulated within certain tolerance limits in a narrow range around the optimal perfusion pressure and kept largely constant. In particular, however, it is possible to avoid over-perfusion and the associated hemorrhagic tissue infarctions even if the outflow of the perfusate in the tissue is disturbed. After an inadmissible increase in the arterial pressure, further perfusion of fluid only takes place again when the pressure has dropped below the predetermined target value.

In retroinfusion, preventing a significant increase in coronary vein pressure above a pre-set threshold during a pumping interval prevents it from becoming potentially dangerous

Peak pressure increases, which could cause damage to the vascular wall and, in extreme cases, vascular rupture.

The diastolic, venous-arterial pressure gradient, which can be constantly adjusted with the device according to the invention, allows an extremely effective retroinfusion, since on the one hand the optimal one There is a pressure gradient for nutritional circulation and, on the other hand, over-perfusion is avoided.

Since the individually different coronary vein pressure, from which there is an increased outflow of retro-infused arterial blood into the systematic circulation, can be determined by means of the plateau pressure in coronary vein occlusion before the interruption of the antegrade perfusion, the invention enables the setting of the optimal coronary vein pressure range for each patient.

Above all, however, both the basic metabolism and the regional myocardial function in the ischemia area are significantly improved compared to the known method. The effectiveness of myocardial protection is significantly increased, especially in patients with low arterial collateralization. Damage to the retro-infused veins can be practically excluded with the method according to the invention. Initial clinical tests suggest that the risk of complications can be reduced in angioplasty.

However, the method and the device according to the invention for the selective perfusion of body vessels controlled by vascular pressure is not only limited to applications for short-term ischemia protection. In addition, longer-term applications of the method are possible, for example in the case of complications with permanent occlusion of the coronary artery as a bypass until operative, emergency bypass treatment. This longer-term ischemia protection is only made possible by the high effectiveness of the tissue supply with the method according to the invention. In particular, if the aspirated venous blood, cleaned and defoamed, is reinfused into a patient's vein, a longer-term use of the retroinfusion method according to the invention is possible while maintaining the functional metabolism. Another area of application is the identification of chronic but reversible regional left ventricular dysfunction, which is also referred to as so-called "hybernating myocardium". In addition to nuclear medicine methods and NMR methods, the method according to the invention can enable a determination of the myocardial metabolism, which enables a differentiation of the necrotic or scarred myocardial tissue from myocardial cells which are still potentially metabolically active. Here, for example to clarify the possible success of a bypass operation, retrograde perfusion can be used to determine whether and to what extent the myocardial function can be restored by improving nutritional perfusion.

Another possible field of application of the invention is already the perfusion or reinfusion of in vitro gene therapy-treated cells into the patient's body.

A preferred embodiment of the invention is explained below with reference to the accompanying drawings. The exemplary embodiment deals with the case of retroinfusion of body veins, but is essentially also transferable to the perfusion of arteries. The essential difference in the perfusion of arteries is that blood is not aspirated and therefore a three-barrel catheter can be used.

The drawing shows:

FIG. 1 shows a schematic representation of a device according to the invention for the selective suction and retroinfusion of body veins controlled by venous pressure;

Fig. 2 shows a preferred embodiment of the vein side

End of the retroinfusion line of the invention Device, the line in the present case being designed as a four-barrel balloon catheter;

3 shows a cross section along the line III-III of the catheter of FIG. 2.

Fig. 4 is a detailed representation of a preferred

Embodiment of the flow controller of the device of Fig. 1;

Fig. 5 shows the schematic representation of an application of the present invention in myocardial protection

Angioplasty;

6 shows graphs of the time course of certain system parameters when carrying out the method according to the invention.

FIG. 1 shows a preferred embodiment of the device 100 according to the invention for selective suction and retroinfusion of body veins controlled by venous pressure. The device has a hose line 60, in the present case four-pipe, which is inserted as a retroinfusion catheter into the body vein 200 to be infused (for example the AlV vein). At the proximal (vein-side) tube end, a sealing means 65 is provided, which is advantageously an inflatable balloon that seals the vein 200 with respect to the line 60, but at the same time allows fluid to pass from the tube line into the vein or vice versa. For this purpose, a supply line 61 is provided in particular, through which fluid can be pumped into the vein 200. For this purpose, the supply line is connected at its distal end (opposite the venous end) to a fluid supply 80. The fluid supply 80 comprises a pressurized fluid reservoir 81, the pressure in the reservoir being monitored by means of a pressure sensor 82. If it is if the fluid to be retro-infused is the patient's own blood, the reservoir 81 can be connected via a pump 83 to a body artery 300 (eg to the femoral artery) of the patient. In this case, blood is drawn out of the artery 300 and, if necessary, passed into the reservoir 81 via an air trap and / or defoamer 84 and a blood filter 85. Means 30 for regulating the fluid flow are provided on the feed line 61. This flow controller 30 includes, in particular, a closure valve 34, with the aid of which the connection between reservoir 81 and vein 200 can be completely interrupted. In a particularly simple embodiment of the flow regulator, the supply line 61 is designed in the region of the regulator as an elastically flexible hose, the flow regulator 30 comprising a clamping member 31 acting on this hose, which is connected via a

Electric motor, preferably a stepper motor 32, is actuated. The retro-infused fluid flow is regulated by squeezing the hose line to a greater or lesser extent. The intravenous pressure in the body vein 200 serves as a measure of the fluid flow to be infused. For this purpose, the retroinfusion catheter 60 has a measuring line 63 which establishes a communicating connection between a pressure sensor 51 arranged at the distal end of the measuring line 63 and the inside of the vein. However, the pressure sensor can also be provided as a proximal pressure sensor 52 on the venous end 66 of the hose line 60. In this case, a three-barrel catheter can also be used, wherein the electrical connection of the pressure sensor 52 to the means for measuring the venous pressure 50 can be passed through one of the remaining lumens of the catheter.

The intravenous pressure values measured in this way are regulated by a control unit 10, which adjusts the clamping member accordingly via the stepper motor 32 of the flow regulator 30. An ultrasonic measuring head 35 can also be provided on the feed line 61, which is used on the one hand for the detection of air bubbles in the fluid to be retrofused and on the other hand for the determination of the fluid flow itself. The Ultrasonic measuring head 35 has an ultrasonic transmitter and an ultrasonic receiver, the reflected ultrasonic signal being used for the detection of air bubbles and the Doppler-shifted ultrasonic signal for determining the fluid flow.

Another lumen of the catheter is a suction line 62, which is used to draw blood or retroinfusate from the patient's vein 200. The suction device 90 comprises a shut-off valve 91, a vacuum pump 92 and a container 93 for collecting the extracted fluid. If necessary, provision can be made not to collect and discard the extracted fluid, but rather to return it to the patient in a cleaned state. This is particularly useful in long-term applications of the device according to the invention. This is a

Intermediate reservoir 94 is provided, the blood collected there being returned to the patient in another vein 400 via a roller pump 95 and an air trap 96 and possibly a blood filter.

For an effective retroinfusion, it is important that the vein 200 to be infused is sealed upstream, as seen in the direction of infusion, so that the retroinfusate flows exclusively into the tissue area to be supplied. For this purpose, a pneumatically inflatable balloon is provided at the proximal end 66 of the catheter 60 as a sealing means 65. A fourth lumen of the catheter therefore forms the control line 64, which does not open into the vein 200, but rather connects the balloon 65 to a pressure-controlled balloon pump 70. A pressure sensor 71 for the balloon pressure is provided on line 64 for pressure control. When the catheter is inserted into the vein to be retrofused, the balloon 65 can be inflated by pumping in air, but possibly also by pumping in a liquid. It then closes the vein tightly at the proximal end of the hose line 60, but also the communicating connection between the supply line 61, the suction line 62 and the pressure measurement line 63 the inside of the vein 200 remains guaranteed.

FIG. 2 shows the proximal end of the retroinfusion catheter 60 of the retroinfusion device 100 shown in FIG. 1, which is inserted into the vein. The individual lines 61, 62, 63, 64 of the four-barrel catheter 60 are welded together in the section of the catheter that can be inserted into the patient and separate into individual lines only outside the patient. For example, the supply line 61 does not have to be a continuous line, but can, outside the patient, be connected to a further line to the supply reservoir 61 via a coupling piece (not shown).

FIG. 3 shows a cross section along the line III-III of the proximal end of the catheter of FIG. 2. The balloon is shown in the inflated position and closes the area between the line 60 and the vein 200 tightly.

FIG. 4 shows an enlarged detailed illustration of a preferred embodiment of the flow controller of the device of FIG. 1. In this area, the feed line 61 consists of an elastic hose and is pressed together by a clamping member 31 designed as a crossbar. The crossbar is actuated by a stepper motor 32, on the shaft of which an eccentric control disk is provided, which acts on the crossbar 31. The clock frequency of the stepper motor is chosen so that a new fluid flow in the feed line 61 can be set in less than 25 ms. The corresponding control takes place via the control unit 10, which calculates the required position of the clamping member from the respectively measured pressure and in particular the current pressure curve and sends corresponding instructions to the stepper motor. The line 61 rests on a counter bearing 36, which prevents movement of the line when squeezed together. A typical application of the present invention is shown schematically in FIG. It is used for myocardial protection during angioplasty. A coronary artery 500 narrowed by arteriosclerotic plaque is expanded by means of a balloon catheter 510. As long as balloon 515 of the balloon catheter is inflated, the area of myocardium 530 normally supplied by this artery is no longer adequately supplied with oxygen and nutrients. For this purpose, a vein 200 draining this myocardial area is inserted

Retroinfusion catheter 60 of the device according to the invention inserted under X-ray control. Oxygen and nutrient-containing blood drawn from another artery of the patient is retroinfused through line 60 into the ischemic area, so that a functional impairment of this area is prevented.

In order to carry out the method according to the invention in myocardial protection, the patient's vein to be retrofused is dependent on the one in question

Myocardial area selected and the retroinfusion catheter 60 of the device 100 according to the invention preferably advanced under X-ray control in the vicinity of the myocardial area to be protected. Depending on whether venous blood flow is present or not, the intravenous pressure is determined or an amount of fluid that increases with each pumping interval is infused and the resulting plateau pressure is measured. From this the desired setpoint of the intravenous pressure can be determined during the retroinfusion intervals. The desired value preferably corresponds to the desired plateau pressure, but it can also be selected somewhat higher or lower.

The retroinfusion with blood or another fluid is synchronized with the heartbeat of the patient in the method according to the invention. For example, a

Electrocardiogram derived with an EKG device 20 (see Figure 1). The time course of some is shown in FIG important system parameters during the implementation of the method according to the invention. The control unit 10 evaluates the R wave 612 of the EKG lead 610. The retro-infusion or suction phases are synchronized with this R-wave of the cardiac cycle. Line 614 shows that

Trigger phase for retro-infusing fluid. This phase preferably begins after 15 to 50% of an R-R interval. Line 620 shows the current position of the flow controller, with changes upward increasing and changes downward decreasing the flow. Curve 630 shows the current pressure in the vein to be retrofused, with horizontal line 632 representing the preselected target pressure. The unit of pressure here is mmHg.

Line 640 shows the retro-infused fluid volume in ml / min. As shown in the drawing, it is possible with the method according to the invention to maintain the desired intravenous target pressure well.

Blood or retroinfusate is drawn out of the vein 200 between the trigger phases.

Typically, approximately 0.5 to 1.5 ml of fluid are infused per pump interval. The average pump volume is between 30 and 150 ml / min. However, these values are influenced by the catheter volume used, the catheter length and the form in the supply-side high-pressure system.

Typical retroinfusion pressures (target values) are between 30 and 110 mmHg, depending on the patient and the retro-infused vein.

Claims

 P a t e n t a n s r u c h e l. Method for the selective pressure perfusion of body vessels with fluids, in which a tube line (60) open at the proximal end for the perfusion of a tissue region with fluids is introduced into a patient's body vessel (200) to be perfused, the vessel (200) opposite the line ( 60) seals in the area of its proximal end and pumps the fluid into the vessel, characterized in that one specifies a specific setpoint of the internal pressure of the vessel, measures the internal pressure of the vessel, and regulates the perfused fluid flow during pumping in such a way that the setpoint of the internal pressure of the vessel is adhered to as precisely as possible. 2. The method according to claim 1, characterized in that the fluid is pumped periodically into the vessel (200) at intervals, wherein the pumping intervals are synchronized with the heartbeat of the patient. 3. The method according to claim 1, characterized in that the fluid is continuously pumped into the vessel (200). 4. The method according to any one of claims 1 to 3, characterized in that the vessel (200) is an artery which supplies the tissue region to be protected with blood. 5. The method according to claim 4, characterized in that one selects the target value of the internal arterial pressure so that the nutritive perfusion is maintained. 6. The method according to claim 2, characterized in that the vessel (200) is a vein, wherein one periodically infuses the fluid via the hose line (60) into the vein and one draws blood out of the vein via the hose line (60). 7. The method according to claim 6, characterized in that the pumping and suction intervals are synchronized with the heartbeat of the patient. 8. The method according to claim 7, characterized in that the target value of the internal vein pressure is determined by infusing an increasing fluid flow with each pumping interval with a sealed vein and a lack of venous blood flow and measuring the internal vein pressure, the target value being the plateau pressure which forms in the vein is chosen. 9. The method according to claim 7, characterized in that one determines the target value of the internal venous pressure by the with a sealed vein and existing venous blood flow Internal vein pressure is measured, the plateau pressure of the venous pressure peaks forming in the vein being selected as the target value. 10. The method according to any one of claims 1 to 9, characterized in that the fluid to be infused is an oxygen carrier. 11. The method according to claim 10, characterized in that the oxygen carrier is blood or a blood substitute. 12. The method according to claim 11, characterized in that arterial blood is withdrawn from the patient, this blood is optionally purified, freed of air bubbles and perfused or retroinfused into the vessel (200). 13. The method according to any one of claims 1 to 12, characterized in that the fluid contains therapeutic or diagnostic agents. 14. The method according to any one of claims 6 to 13, characterized in that, if necessary, the blood drawn off in the suction intervals is defoamed, freed from air bubbles and fed back to the patient via another body vein (400). 15. Device for the vascular pressure-controlled selective perfusion of body vessels with a fluid, in particular for carrying out the method according to one of claims 1 to 14, comprising: a hose line (60) which can be inserted into a body vessel (200) of a patient and is open at the proximal end and which a pressurized fluid can be fed which is to be pumped into the body vessel (200), an expandable sealing means (65) being provided at the proximal end, which seals the vessel (200) with respect to the line (60), characterized in that In addition, means (50) for measuring the internal pressure of the vessel and a flow regulator (30) for the line (60) are provided, the control unit (10) via flow regulator (30) keeping a specific internal pressure of the vessel as constant as possible during pumping. 16. The apparatus according to claim 15, wherein the vessel (200) is a vein, characterized in that the line (60) is connected to a suction device (90) for blood from the patient's vein (200) and a control unit (10) is provided which receives signals from the patient's heartbeat and which defines pumping and suction intervals which are synchronized with the patient's cardiac cycle. 17. The device according to one of claims 15 or 16, characterized in that the line (60) is a multi-path catheter. 18. The apparatus according to claim 17, characterized in that the catheter is an at least four-course venous catheter for retroinfusion, wherein a supply line (61) for the fluid, a suction line (62) for the drawn blood, a measuring line (63) for determining the internal venous pressure and a control line (64) for the expandable sealing means (65) is provided. 19. The apparatus according to claim 17, characterized in that the catheter is an at least three-barrel arterial catheter Perfusion is provided, a supply line (61) for the fluid, a measuring line (63) for determining the internal artery pressure and a control line (64) for the enlargeable sealing means (65) being provided. 20. Device according to one of claims 15 to 19, characterized in that the sealing means (65) is a pressure-controlled inflatable balloon. 21. Device according to one of claims 18 to 20, characterized in that the measuring line (63) communicates with the inside of the vessel at one end and has a pressure sensor (51) at its other end. 22. Device according to one of claims 15 to 20, characterized in that the means (50) for measuring the venous pressure comprise a pressure sensor (52) which is arranged at the proximal end of the line (60) and is connected to the control unit (10). REPLACEMENT SHEET {RULE 26) 23. The device according to one of claims 15 to 22, characterized in that the feed line (60, 61) in the area of the flow control (30) is formed by an elastically flexible hose, the flow control (30) being a clamping element operated by an electric motor ( 31), which compresses the elastic tube to a greater or lesser extent and thus controls the flow of the fluid into the vessel. 24. The device according to one of claims 15 to 23, characterized in that the distal end of the supply line (60,61) is connected to a pressurized reservoir (81) for the fluid, wherein a pressure sensor (82) for monitoring the pressure is provided in the reservoir (81). 25. The device according to claim 24, characterized in that the reservoir (81) via a roller pump (83) with the blood drawn from an artery (300) of the patient is fed. 26. Device according to one of claims 16 to 25, characterized in that the suction device (90) comprises a vacuum pump (92) and a reservoir (93) for the sucked blood. 27. The device according to one of claims 16 to 26, characterized in that the suction device (90), a reservoir (94), a roller pump (95) and an air trap (96) are connected together to form a vein (400) of the patient to supply the sucked blood clean.